What i'm asking is will my credit go down that much and if I decide to voluntary repo? I'm currently at 650. If I can't get a FHA loan what are my options for buying a home with a repo on my credit score?
FHA credit requirements are such that you can qualify for an FHA loan with 3.5% down payment if you have a credit score of 580 or higher. If lower than 580, a 10% down payment. There are other factors to your approval, of course, but they accommodate some fairly low credit scores.
According to this Experian article, repossession, voluntary or not, is "very negative" for your credit score. No specific numbers given, but sounds like it's best to avoid if at all possible.
Note that voluntary repossession doesn't get you out of a loan, you'd still owe the difference between loan amount and what the vehicle sells for.
In general, yes, people can get FHA loans with a repossession on their credit history, but it does make mortgage approval less likely overall. Most repossessions are accompanied with a slew of late payments, which really do a number on the credit score, a repossession with no late payments would be better, but again, best to be avoided if possible.